[v10,1/3] pipe-source: implement autosuspend behavior

Submitted by Raman Shishniou on March 20, 2018, 12:27 p.m.

Details

Message ID 1521548857-11194-1-git-send-email-rommer@ibuffed.com
State New
Headers show
Series "Series without cover letter" ( rev: 1 ) in PulseAudio

Not browsing as part of any series.

Commit Message

Raman Shishniou March 20, 2018, 12:27 p.m.
Currently the pipe-source will remain running even if no
writer is connected and therefore no data is produced.
This patch prevents this by auto-suspending source
when all writers are disconnected.
---
 src/modules/module-pipe-source.c | 207 ++++++++++++++++++++++++++++++++-------
 1 file changed, 171 insertions(+), 36 deletions(-)

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diff --git a/src/modules/module-pipe-source.c b/src/modules/module-pipe-source.c
index f8284c1..c069dd4 100644
--- a/src/modules/module-pipe-source.c
+++ b/src/modules/module-pipe-source.c
@@ -33,6 +33,7 @@ 
 #include <sys/filio.h>
 #endif
 
+#include <pulse/rtclock.h>
 #include <pulse/xmalloc.h>
 
 #include <pulsecore/core-error.h>
@@ -62,6 +63,18 @@  PA_MODULE_USAGE(
 #define DEFAULT_FILE_NAME "/tmp/music.input"
 #define DEFAULT_SOURCE_NAME "fifo_input"
 
+struct pipe_source_msg {
+    pa_msgobject parent;
+};
+
+typedef struct pipe_source_msg pipe_source_msg;
+PA_DEFINE_PRIVATE_CLASS(pipe_source_msg, pa_msgobject);
+
+enum {
+    PIPE_SOURCE_SUSPEND,
+    PIPE_SOURCE_RESUME
+};
+
 struct userdata {
     pa_core *core;
     pa_module *module;
@@ -71,7 +84,15 @@  struct userdata {
     pa_thread_mq thread_mq;
     pa_rtpoll *rtpoll;
 
+    pipe_source_msg *msg;
+    pa_usec_t timestamp;
+    size_t pipe_size;
+
+    bool writer_connected;
+    bool suspended_by_user;
+
     char *filename;
+    int corkfd;
     int fd;
 
     pa_memchunk memchunk;
@@ -90,6 +111,37 @@  static const char* const valid_modargs[] = {
     NULL
 };
 
+/* Called from main context */
+static int pipe_source_process_msg(
+        pa_msgobject *o,
+        int code,
+        void *data,
+        int64_t offset,
+        pa_memchunk *chunk) {
+
+    struct userdata *u = (struct userdata *) data;
+
+    pa_assert(u);
+
+    switch (code) {
+        case PIPE_SOURCE_SUSPEND:
+            pa_log_debug("Suspending source %s because no writers left", u->source->name);
+            pa_source_suspend(u->source, true, PA_SUSPEND_UNAVAILABLE);
+            break;
+
+        case PIPE_SOURCE_RESUME:
+            pa_log_debug("Resuming source %s", u->source->name);
+            pa_source_suspend(u->source, false, PA_SUSPEND_UNAVAILABLE);
+            break;
+
+        default:
+            pa_assert_not_reached();
+    }
+
+    return 0;
+}
+
+/* Called from thread context */
 static int source_process_msg(
         pa_msgobject *o,
         int code,
@@ -102,16 +154,11 @@  static int source_process_msg(
     switch (code) {
 
         case PA_SOURCE_MESSAGE_GET_LATENCY: {
-            size_t n = 0;
+            pa_usec_t now;
 
-#ifdef FIONREAD
-            int l;
+            now = pa_rtclock_now();
+            *((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
 
-            if (ioctl(u->fd, FIONREAD, &l) >= 0 && l > 0)
-                n = (size_t) l;
-#endif
-
-            *((int64_t*) data) = pa_bytes_to_usec(n, &u->source->sample_spec);
             return 0;
         }
     }
@@ -119,8 +166,41 @@  static int source_process_msg(
     return pa_source_process_msg(o, code, data, offset, chunk);
 }
 
+/* Called from thread context */
+static int source_set_state_in_io_thread_cb(pa_source *s, pa_source_state_t new_state, pa_suspend_cause_t new_suspend_cause) {
+    struct userdata *u;
+
+    pa_assert(s);
+    pa_assert_se(u = s->userdata);
+
+    switch (new_state) {
+
+        case PA_SOURCE_SUSPENDED:
+
+            u->suspended_by_user = !!(new_suspend_cause & ~PA_SUSPEND_UNAVAILABLE);
+            break;
+
+        case PA_SOURCE_IDLE:
+        case PA_SOURCE_RUNNING:
+
+            if (s->thread_info.state == PA_SOURCE_SUSPENDED || s->thread_info.state == PA_SOURCE_INIT) {
+                u->timestamp = pa_rtclock_now();
+                u->suspended_by_user = false;
+            }
+            break;
+
+        case PA_SOURCE_UNLINKED:
+        case PA_SOURCE_INIT:
+        case PA_SOURCE_INVALID_STATE:
+            ;
+    }
+
+    return 0;
+}
+
 static void thread_func(void *userdata) {
     struct userdata *u = userdata;
+    struct pollfd *pollfd;
     int read_type = 0;
 
     pa_assert(u);
@@ -129,30 +209,29 @@  static void thread_func(void *userdata) {
 
     pa_thread_mq_install(&u->thread_mq);
 
+    u->memchunk.memblock = pa_memblock_new(u->core->mempool, u->pipe_size);
+    u->timestamp = pa_rtclock_now();
+
+    /* Close our writer here to suspend source if no writers left */
+    pa_assert_se(pa_close(u->corkfd) == 0);
+    u->corkfd = -1;
+
+    pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
+
     for (;;) {
         int ret;
-        struct pollfd *pollfd;
-
-        pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
 
-        /* Try to read some data and pass it on to the source driver */
-        if (u->source->thread_info.state == PA_SOURCE_RUNNING && pollfd->revents) {
+        /* Try to read some data if there are any events */
+        if (pollfd->revents) {
             ssize_t l;
             void *p;
 
-            if (!u->memchunk.memblock) {
-                u->memchunk.memblock = pa_memblock_new(u->core->mempool, pa_pipe_buf(u->fd));
-                u->memchunk.index = u->memchunk.length = 0;
-            }
-
-            pa_assert(pa_memblock_get_length(u->memchunk.memblock) > u->memchunk.index);
+            pa_assert(u->memchunk.length == 0);
 
             p = pa_memblock_acquire(u->memchunk.memblock);
-            l = pa_read(u->fd, (uint8_t*) p + u->memchunk.index, pa_memblock_get_length(u->memchunk.memblock) - u->memchunk.index, &read_type);
+            l = pa_read(u->fd, p, pa_memblock_get_length(u->memchunk.memblock), &read_type);
             pa_memblock_release(u->memchunk.memblock);
 
-            pa_assert(l != 0); /* EOF cannot happen, since we opened the fifo for both reading and writing */
-
             if (l < 0) {
 
                 if (errno == EINTR)
@@ -162,23 +241,51 @@  static void thread_func(void *userdata) {
                     goto fail;
                 }
 
+            } else if (l == 0) {
+
+                if (u->writer_connected) {
+                    pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_SUSPEND, u, 0, NULL, NULL);
+
+                    if ((u->corkfd = pa_open_cloexec(u->filename, O_WRONLY, 0)) < 0) {
+                        pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+                        goto fail;
+                    }
+
+                    u->writer_connected = false;
+                }
+
             } else {
 
                 u->memchunk.length = (size_t) l;
-                pa_source_post(u->source, &u->memchunk);
-                u->memchunk.index += (size_t) l;
+                u->timestamp = pa_rtclock_now();
 
-                if (u->memchunk.index >= pa_memblock_get_length(u->memchunk.memblock)) {
-                    pa_memblock_unref(u->memchunk.memblock);
-                    pa_memchunk_reset(&u->memchunk);
+                if (!u->writer_connected) {
+                    pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_RESUME, u, 0, NULL, NULL);
+                    u->writer_connected = true;
                 }
 
-                pollfd->revents = 0;
             }
         }
 
-        /* Hmm, nothing to do. Let's sleep */
-        pollfd->events = (short) (u->source->thread_info.state == PA_SOURCE_RUNNING ? POLLIN : 0);
+        /* Post data to source */
+        if (PA_SOURCE_IS_OPENED(u->source->thread_info.state)) {
+
+            if (u->writer_connected && u->corkfd >= 0) {
+                pa_assert_se(pa_close(u->corkfd) == 0);
+                u->corkfd = -1;
+            }
+
+            if (u->memchunk.length > 0) {
+                pa_source_post(u->source, &u->memchunk);
+                pa_memblock_unref(u->memchunk.memblock);
+                u->memchunk.memblock = pa_memblock_new(u->core->mempool, u->pipe_size);
+                u->memchunk.length = 0;
+            }
+
+        } else if (u->suspended_by_user)
+            u->memchunk.length = 0;
+
+        pollfd->events = u->memchunk.length ? 0 : POLLIN;
 
         if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
             goto fail;
@@ -188,9 +295,12 @@  static void thread_func(void *userdata) {
 
         pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
 
-        if (pollfd->revents & ~POLLIN) {
-            pa_log("FIFO shutdown.");
-            goto fail;
+        if (pollfd->revents & ~(POLLIN|POLLHUP)) {
+            pa_log("FD error: %s%s%s%s",
+                   pollfd->revents & POLLOUT ? "POLLOUT " : "",
+                   pollfd->revents & POLLERR ? "POLLERR " : "",
+                   pollfd->revents & POLLPRI ? "POLLPRI " : "",
+                   pollfd->revents & POLLNVAL ? "POLLNVAL " : "");
         }
     }
 
@@ -238,13 +348,26 @@  int pa__init(pa_module *m) {
         goto fail;
     }
 
+    if (!(u->msg = pa_msgobject_new(pipe_source_msg)))
+        goto fail;
+
+    u->msg->parent.process_msg = pipe_source_process_msg;
+
     u->filename = pa_runtime_path(pa_modargs_get_value(ma, "file", DEFAULT_FILE_NAME));
 
     if (mkfifo(u->filename, 0666) < 0) {
         pa_log("mkfifo('%s'): %s", u->filename, pa_cstrerror(errno));
         goto fail;
     }
-    if ((u->fd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
+
+    if ((u->corkfd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
+        pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+        goto fail;
+    }
+
+    u->writer_connected = true;
+
+    if ((u->fd = pa_open_cloexec(u->filename, O_RDONLY, 0)) < 0) {
         pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
         goto fail;
     }
@@ -284,18 +407,24 @@  int pa__init(pa_module *m) {
         goto fail;
     }
 
-    u->source->parent.process_msg = source_process_msg;
     u->source->userdata = u;
+    u->source->parent.process_msg = source_process_msg;
+    u->source->set_state_in_io_thread = source_set_state_in_io_thread_cb;
 
     pa_source_set_asyncmsgq(u->source, u->thread_mq.inq);
     pa_source_set_rtpoll(u->source, u->rtpoll);
-    pa_source_set_fixed_latency(u->source, pa_bytes_to_usec(pa_pipe_buf(u->fd), &u->source->sample_spec));
+
+    u->pipe_size = pa_pipe_buf(u->fd);
+    u->pipe_size = PA_MIN(pa_mempool_block_size_max(m->core->mempool), u->pipe_size);
+    pa_source_set_fixed_latency(u->source, pa_bytes_to_usec(u->pipe_size, &u->source->sample_spec));
 
     u->rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1);
     pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
     pollfd->fd = u->fd;
     pollfd->events = pollfd->revents = 0;
 
+    u->suspended_by_user = false;
+
     if (!(u->thread = pa_thread_new("pipe-source", thread_func, u))) {
         pa_log("Failed to create thread.");
         goto fail;
@@ -360,6 +489,12 @@  void pa__done(pa_module *m) {
         pa_xfree(u->filename);
     }
 
+    if (u->msg)
+        pa_xfree(u->msg);
+
+    if (u->corkfd >= 0)
+        pa_assert_se(pa_close(u->corkfd) == 0);
+
     if (u->fd >= 0)
         pa_assert_se(pa_close(u->fd) == 0);
 

Comments

On 20.03.2018 13:27, Raman Shyshniou wrote:
> Currently the pipe-source will remain running even if no
> writer is connected and therefore no data is produced.
> This patch prevents this by auto-suspending source
> when all writers are disconnected.

The series looks nearly good now, only two small comments remaining.

> @@ -102,16 +154,11 @@ static int source_process_msg(
>       switch (code) {
>   
>           case PA_SOURCE_MESSAGE_GET_LATENCY: {
> -            size_t n = 0;
> +            pa_usec_t now;
>   
> -#ifdef FIONREAD
> -            int l;
> +            now = pa_rtclock_now();
> +            *((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
>   
> -            if (ioctl(u->fd, FIONREAD, &l) >= 0 && l > 0)
> -                n = (size_t) l;
> -#endif
> -
> -            *((int64_t*) data) = pa_bytes_to_usec(n, &u->source->sample_spec);
>               return 0;
>           }
>       }
It is possible, that the memchunk contains some data you have not posted
when you are resuming from auto suspend. So you have to add the data in
the memchunk to the latency.